Dragline chain

ABSTRACT

A method for maintaining a chain or chain link comprises inspecting the chain or chain link for signs of wear without using tools and changing the orientation of the chain or chain link or replacing the chain or chain link if signs of wear are detected.

TECHNICAL FIELD

The present disclosure relates to chain assemblies that are used indragline mining operations and the like. More specifically, the presentdisclosure relates to a dragline bucket chain assembly that includeswear indicators.

BACKGROUND

Referring initially to FIG. 1, chains 100 have historically been used indragline buckets 102 in the hoist and drag circuits. Some riggingconfigurations also use chains in the dump circuit (single dump blocksystems). Chains 100 have in the past been cast, forged, comprisedstructural plate, etc.

These chains comprise a plurality of links that are interconnected andengage each other in the region called the “bite” region of the links.This usually corresponds to the inside radial portion of an end of thechain link. This area is subjected to tension loads in use and/orabrasion from the material located in the work area. Over time, thisbite region may wear down, compromising the strength of the chain link,and therefore, of the chain as a whole. Consequently, the chain may needto be replaced.

Similarly, the middle portions (sometimes referred to as “rails”) of thechain link, situated between the ends of the chain link may also besubject to wear from abrasion from the material located in the workarea, necking due to tensile loads, etc. Once the middle portion of thechain link becomes too thin, the chain link strength and the overallchain strength may be compromised. Consequently, the chain may need tobe replaced.

Current practices to monitor these various types of wear includeinspection methods to determine when the chains need to be replaced,rotated ninety degrees, or flipped. In some cases, gauges, measuringtapes, and calipers may be employed to determine if a minimum dimensionof the chain link has been reached. When inspecting the bite region onthe chain links, it may be necessary to pry the chain link apart tomeasure and inspect. This can be time consuming and may damage the chainundesirably.

Accordingly, it is desirable to develop a better method for inspectingchain links for wear than has yet been devised.

SUMMARY OF THE DISCLOSURE

A chain link according to an embodiment of the present disclosurecomprises a body including two end portions and two middle portionsconnecting the two end portions together, wherein at least one middleportion defines at least one region including at least one wearindicator.

A chain assembly according to an embodiment of the present disclosurecomprises at least two chain links interconnected with each other, andat least one of the chain links includes a body including two endportions, wherein at least one end portion defines a bite regionincluding a bite contact surface configured to contact the other chainlink and that defines a load vector, the at least one end portionincluding a first portion with a reduced cross-section defining a firstthickness measured along a direction that is non-parallel to the loadvector, and a raised rib disposed between the bite region and the firstportion along a direction parallel with the load vector, the raised ribdefining a second thickness along a direction that is non-parallel tothe load vector, wherein the second thickness is greater than the firstthickness.

A method for maintaining a chain or chain link according to anembodiment of the present disclosure comprises inspecting the chain orchain link for signs of wear without using tools and changing theorientation of the chain or chain link or replacing the chain or chainlink if signs of wear are detected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a dragline bucket that is suspended and pulledusing chains as is known in the art.

FIG. 2 is a perspective view of a chain that may be used in anapplications such as shown in FIG. 1 shown in isolation from a bucket orany other apparatus, giving an example of a chain according to anembodiment of the present disclosure where a plurality of chain linkshave wear indicators and/or a rib proximate the bite area of the chain.

FIG. 3 is a perspective view of a chain link according to an embodimentof the present disclosure showing wear indicators and a rib proximatethe bite area of the chain link. The chain link is shown in asubstantially horizontal orientation.

FIG. 4 is an alternate perspective view of the chain link of FIG. 3shown in a substantially vertical orientation.

FIG. 5 is a top view of the chain link of FIG. 3 or side view of thechain link of FIG. 4.

FIG. 6 is a sectional view of the chain link of FIG. 5 taken along lines6-6 thereof, depicting the addition of a rib in the bite area of thechain link member.

FIG. 7 is a sectional view of the chain link of FIG. 5 taken along lines7-7 thereof, depicting the configuration of the pockets on the middleportions of the chain link, which act as wear indicators.

FIG. 8 is a side view of the chain link of FIG. 3 or the bottom view ofthe chain link of FIG. 4.

FIGS. 9 and 10 illustrate the chain link of FIG. 3 where the bite areaof the chain link has reached a first stage of wear.

FIGS. 11 and 12 illustrate the chain link of FIGS. 9 and 10 after thebite area of the chain link has reached a second stage of wear,indicating that the chain link will need to be replaced soon.

FIGS. 13 and 14 show the bite area of the chain link of FIGS. 11 and 12after the chain link has reached a third stage of wear, requiring thatthe chain link be replaced.

FIGS. 15 and 16 depict the chain link of FIG. 3 where both the bottomsurface and the side surfaces of the chain link have been worn away,requiring replacement of the chain link.

FIGS. 17 and 18 illustrate the chain link of FIG. 3 where the bottomsurface of the chain link has been worn away, requiring at least thatthe chain link be rotated ninety degrees from the horizontal to thevertical orientation.

FIGS. 19 and 20 depict the chain link of FIG. 3 where the side surfacesof the chain have been worn away, requiring that the chain link berotated ninety degrees from the horizontal to the vertical orientation.

FIG. 21 contains a flowchart delineating a method of using ormaintaining a chain link having a rib in its bite area and/or wearindicators on either of its middle portions.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the disclosure,examples of which are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts. In some cases, a referencenumber will be indicated in this specification and the drawings willshow the reference number followed by a letter for example, 100a, 100bor by a prime for example, 100′, 100″ etc. It is to be understood thatthe use of letters or primes immediately after a reference numberindicates that these features are similarly shaped and have similarfunction as is often the case when geometry is mirrored about a plane ofsymmetry. For ease of explanation in this specification, letters andprimes will often not be included herein but may be shown in thedrawings to indicate duplications of features, having similar oridentical function or geometry, discussed within this writtenspecification.

In various embodiments, a chain link with wear indicators that do notrequire the use of gauges, measuring tapes, calipers or the like may beprovided. This may make it safer to inspect without having to pry chainlinks apart to inspect the bite regions. In certain embodiments, araised rib may be provided in the bite region that may serve twofunctions. First, the raised rib may provide a wear indicator. Second,the raised rib may provide increased bearing surface area (such as 15%or more), strengthening the chain link and possibly slowing down thewear rate in the bite region of the chain link. Various embodiments ofthis type of chain link may allow the user to use a method of use ormonitoring the wear and replacing a chain link, a chain, or changing theorientation of a chain link or chain without using tools.

Looking at FIGS. 2 thru 5, a chain assembly 200 according to anembodiment of the present disclosure is illustrated. The chain assembly200 comprises at least two chain links 202, 202′ interconnected witheach other, and at least one of the chain links 202 includes a body 204including two end portions 206. At least one end portion 206 defines abite region 208 including a bite contact surface 210 configured tocontact the other chain link and that defines a load vector L.

As best seen in FIG. 6, this end portion 206 may include a first portion212 with a reduced cross-section defining a first thickness 214 measuredalong a direction that is non-parallel to the load vector L, and araised rib 216 disposed between the bite region 208 and the firstportion 212 along a direction parallel with the load vector L. Theraised rib 216 may define a second thickness 218 along a direction thatis non-parallel to the load vector L, wherein the second thickness 218is greater than the first thickness 214. This raised rib may be used oneither a body or intermediate link 202 or an end link 202″. An end linkmay also have wear indicators as will be later described herein. In someembodiments, an end link or a body link of the chain may lack a raisedrib or wear indicators, etc.

Referring back to FIGS. 2 thru 5, the body 204 defines a center of massC and a Cartesian coordinate system with an X-axis, Y-axis, a Z-axis andan origin O positioned at the center of mass C. For this embodiment,both the end portions 206 define a load vector L for the body 204 forthis chain link 202 and the X-axis of the coordinate system is orientedparallel with the load vector L. The body 204 further includes a firstmiddle portion 220 and a second middle portion 220′ (in some embodimentsthe middle portions may be referred to as rails) connecting the two endportions 206 together, forming an enclosed perimeter. In some cases, thechain link 202 may not form an enclosed perimeter. For the embodimentshown in FIG. 3, the chain link has an oval shape (more specifically a“race track” shape) but other shapes are contemplated such as circular,rectangular, elliptical, etc.

More particularly, the first middle portion 220 and the second middleportion 220′ are straight, extending along a direction parallel to theX-axis. This may not be the case for other embodiments. In some cases,the chain link may not form an enclosed perimeter. The end portion 206defines a first curved portion 222 extending from the first middleportion 220 to the second middle portion 220′ and the raised rib 216extends from the first middle portion 220 to the second middle portion220′ along the first curved portion 222. A first ramp 224 is provided totransition from the lowest part 226 of the middle portion 220 to theraised rib 216.

Focusing on FIG. 6, the first and second thicknesses 214, 218respectively are measured in a direction perpendicular to the loadvector L and the ratio of the second thickness 218 to the firstthickness 214 ranges from 1.1 to 1.5 for some embodiments and moreparticularly about 1.25 for some embodiments. Likewise, the end portion206 defines a first extremity 228 along a direction that is parallel tothe load vector L and the first portion 212 with a reduced cross-sectiondefines a third thickness 230 measured along a direction that isparallel to the load vector L from first extremity 228 to the raised rib216.

Also, the raised rib 216 defines a fourth thickness 232 measured along adirection that is parallel to the load vector L from the first portion212 with a reduced cross-section to the bite contact surface 210, and aratio of the fourth thickness 232 to the third thickness 230 ranges from0.30 to 0.50 and more particularly for some embodiments may beapproximately 0.38. The body 204 further defines a radiused portion 234that transitions from the raised rib 216 to the first portion 212 with areduced cross-section. The radiused portion 234 may have a radius in aplane similar to that shown in FIG. 6 having a value ranging from 0(near the ramp areas) to 1.0 inch. In some embodiments a full radius 234may be employed such there is no straight surface between the raised rib216 and the first portion with reduced cross-section. In such a case,the radius may vary between 0.25 and 4 inches. The radiused portion 234transitioning from the first portion 212 having a reduced cross-sectionto the raised rib 216 may be included when measuring the third thickness230 of the first portion 212. Similarly, any blending radii or the likeat corners may be included when measuring the fourth thickness 232 ofthe raised rib 216, etc. Other transition geometery may be substitutedwith or for a radius such as a chamfer or other curved surface, etc.

Returning to FIGS. 2 thru 5, the middle portion 220 of the chain link202 defines a first bottom region 236 including at least a first onebottom wear indicator 238, and a second side region 240 including atleast a second one side wear indicator 238′. In some embodiments, onlyone region 236, 240 may have a wear indicator 238 for reasons that willbe explained later herein. The second side wear indicator 238′ has anelongated shape extending in a direction parallel to the load vector Land the first bottom wear indicator 238 has an elongated shape extendingin a direction perpendicular to the load vector L.

FIG. 8 shows that the top and bottom parts 227 of the middle portions220 of the chain link 202 are substantially coplanar with the top andbottom extremities of the raised ribs 216. Also, a second ramp 242 isprovided to transition from the top or bottom extremities of the middleportions 220 to the plane of the first portion 212 with a reducedcross-section. Other configurations are possible. Nine pockets 242 areprovided as wear indicators 238 on the top or bottom surface 244 of themiddle portion 220. The middle pocket 242 is centered relative to originO of the Cartesian coordinate system, and hence, the center of mass Cfor the chain link 202. The pockets on the bottom surface are positionedequidistant from each other along the X-axis. The number, configuration,and placement of the wear indicators may be varied for otherembodiments. For example, five to fourteen pockets may be provided on amiddle portion for some embodiments.

In like fashion, looking at FIG. 5, two wear indicators 238 238′ areprovided on the side surfaces 246 of the middle portion 220 of the chainlink 202. They are positioned approximately halfway between the Y-Zplane defined by the coordinate system and the beginning of the curvedportion 222 of the ends 206 of the chain link 202. Again, the number,configuration, and placement of the wear indicators 238 may be variedfor other embodiments. Any of the wear indicators 238 discussed hereinmay be proud (e.g. a rib) or recessed (e.g. a pocket) depending on theembodiment or the application, etc. A strut 248 is provided to help thechain link 202 resist necking when loaded in tension. This strut may beomitted in other embodiments.

Factors that may cause the configuration or placement of the pockets orother wear indicators to vary include the chain thickness, soil wash,material of the chain link, historical data concerning areas with a highwear rate, etc.

Further details of an embodiment of the chain link 202 according to thepresent disclosure will now be discussed with reference to FIGS. 3 thru5. As already alluded to, the body 204 of the chain link 202 includestwo end portions 206 and two middle portions 220 connecting the two endportions 206 together. At least one middle portion 220 defines at leastone region 236, 240 including at least one wear indicator 238. Forexample, the region could be on a side surface 246 or bottom surface 244of the middle portion 220 of the chain link 202. The body 204 defines acenter of mass C and a Cartesian coordinate system with an X-axis,Y-axis, a Z-axis and an origin O positioned at the center of mass C.

Furthermore, the end portions 206 define a load vector L for the body204 of the chain link 202 and the X-axis of the coordinate system isoriented parallel with the load vector L. In this embodiment, the X-axisis often coextensive with the load vector L in use. However, this maynot be the case if the chain link is differently configured or the chainbecomes kinked, causing the bite contact surface 210 to change locationalong the curved portion 222 of the end 206 of the chain link 202, etc.The end portions 206 are C-shaped or half of a circular diameter,facilitating the movement of one chain link relative to another chainlink but other curved or arcuate shapes are possible.

As best seen in FIG. 7 for this embodiment, at least one middle portion220 defines a first surface 250 250′ defining a first surface normal 252252′ that is non-parallel to the X-axis, and the at least one wearindicator 238 238′ is disposed on the first surface 250 250′. This firstsurface 250′ is shown as the side surface 246 in FIG. 7, but may be thebottom or side surface 244, 246 shown in FIG. 7 for example in otherembodiments of the present application, etc. For the bottom surface 244,the first another surface normal 252 is parallel to the Y-axis. For theside surface 246, the first surface normal 252′ is non-parallel to theZ-axis and the Y-axis. In some embodiments, this first surface normal252′ forms an angle α with a direction parallel to the Z-axis thatranges from 5 to 10 degrees. Put another way, the first surface normal252′ forms an angle β with a direction parallel to the Y-axis thatranges from 80 to 85 degrees. These angles may be varied. For example,the side surface may be perpendicular to the Y-axis, etc.

Similarly, for this embodiment as best seen by looking at FIGS. 7 and 8,at least one wear indicator 238 238′ includes a first pocket 242 242′defined by the first surface 250 250′ such as the bottom side surface244 246. The first pocket 242 242′ is elongated along a directionparallel with the Y-axis X-axis defining its maximum dimension 254 254′oriented along the Z-axis X-axis, the first pocket 242 242′ furtherdefining a width 256 256′ along a direction parallel along the X-axisY-axis and a depth 258 258′ along a direction parallel with the Y-axisZ-axis. By way of example, dimension 254 254′ may vary between 0.5 and 5inches for some embodiments, width 256 256′ may vary between 0.12 and1.5 inches in some embodiments, and the depth 258 258′ may vary between1.5 and 7 inches in some embodiments.

Looking at FIGS. 5 and 7, a second surface 250′ 250 such as a sidebottom surface 246 244 may also be provided defining a second surfacenormal 252′ 252 that is non-parallel to the X-axis. This second surface250′ 250 may include a second wear indicator 238 in the form of a secondpocket 242′ 242 that is elongated along a direction parallel with theX-axis Z-axis defining its maximum dimension 254′ 254 oriented along theX-axis Z-axis, the second pocket further defining a width 256′ 256 alonga direction parallel with the Y-axis X-axis and a depth 258′ 258 along adirection parallel with the Z-axis Y-axis. By way of example, dimension254′ 254 may vary between 0.5 and 5 inches for some embodiments, width256′ 256 may vary between 0.12 and 1.5 inches in some embodiments, andthe depth 258′ 258 may vary between 1.5 and 7 inches in someembodiments.

For the embodiment shown FIGS. 5 and 7, the second first pocket 242′defines a bottom extremity 260 positioned along a direction parallelwith the Z-axis and the first second pocket 242 defines an end extremity262 positioned along a direction parallel with the Z-axis. In addition,as best seen in FIG. 7, the Cartesian coordinate system establishes afirst X-Z X-Y plane 264 positioned at the origin of the Cartesiancoordinate system and the body of the chain link defines a second X-ZX-Y plane 266 spaced away from the first X-Z X-Y plane 264 that isdisposed between the bottom extremity 260 of the second first pocket242′ and the end extremity 262 of the first second pocket 242. As aresult, the end extremity 262 of the first second pocket 242 will beworn away before the second first pocket 242′ wears away completely (butwill only be very faintly seen). In some cases, the end extremity 262 ofthe first second pocket 242 and the bottom extremity 260 of the secondfirst pocket 242′ may lie substantially in the same X-Z X-Y plane. Thatis to say, as soon as the second first pocket 242′ is worn away, the endextremity 262′ 262 of the first second pocket 242 may also be worn away.

It is contemplated that the second pocket 242′ 242 and its function maybe replaced by instructing the user that when the end extremity 262 ofthe first pocket 242 242′ is worn away, the side surface 246 has beenworn to or past a minimum acceptable dimension. It is furthercontemplated that the orientation of the second pocket 242′ 242 maychange so that it is elongated along a direction substantially parallelwith the Y-axis so that the first pocket 242 242′ and its function maybe replaced by instructing the user that when the end extremity of thesecond pocket is worn away, the bottom surface 244 has been worn to orpast a minimum acceptable dimension.

The orientation of the pockets on the bottom or top surface may allowmaterial in the work area such as sand or loose material or the like tobe trapped in the pockets. As a consequence, more material may adhere tothe trapped material, forming a protective layer on the underside of thechain link, helping to reduce the wear rate. Similar benefits may beobtained in other regions of the track link depending on theconfiguration of the features and the track link.

For the embodiments shown in the figures, the Cartesian coordinatesystem establishes a X-Y plane, a Y-Z plane, and a first X-Z plane 264.The body 204 of the chain link 202 is shown to be symmetrical about theX-Y plane, the first X-Z plane and the Y-Z plane. This increases theversatility of orientation changes possible for this track link oncesigns of wear occur at one or more places. However, it is contemplatedthat other embodiments may have one, two or no planes of symmetry, etc.

Here are some exemplary dimensions of the chain link. The overall lengthof the chain link in the X direction may range from 4 to 40 inches andthe overall height of the main link member may range from 2 to 20 in theY direction. Often, there is a two to one ratio concerning the length ofthe chain link in the X direction versus its height in the Y direction.A length of the strut in the X direction and height in the Z directionmay be a quarter of the width of the gap (this gap is the distance fromthe inner arcuate surface of one C-shaped end to the inner arcuatesurface of the other C-shaped end, which may range from 4 to 38 inchesfor example). The dimensions of the main cross-section of the chain linkmay be substantially constant around the oval perimeter and may includea height in the Z direction of about half an inch and a thickness in theY direction of about an inch. The thickness of the chain in the Ydirection may range from one to seven inches. Any of the dimensionsdiscussed anywhere herein may vary as needed or desired. Also, theratios of the dimensions discussed herein may be scaled up or down basedon the embodiment or application or may be otherwise varied as needed ordesired.

The chain link may be made from any suitable material including iron,grey cast-iron, steel, etc. Also, the chain link may be integrally cast,forged or may be fabricated and assembled by fastening, welding, pressfitting, etc. two or more pieces together to form the chain link.

FIGS. 9 and 10 illustrate the chain link 202 after it has reached afirst stage of wear in the bite region 208 during the useful life of thechain link. This wear takes place over time due to several factorsincluding tension and rubbing between the links, abrasion from thematerial in the work area, etc. The ratio of the fourth thickness 232 tothe third thickness 230 as shown in FIG. 10 may be approximately 0.1 to1.0 for some embodiments at this stage of wear. The contact surface area210 at this point has not decreased substantially so the chain link 202still has some useful life left.

In FIGS. 11 and 12, the chain link 202 has reached a second stage ofwear in the bite region 208. At this stage, the ratio of the fourththickness 232 to the third thickness 230 approached zero, meaning thatthe contact surface area 210 is about to start decreasing quickly. So,the user would be alerted that it is time to start thinking aboutreplacing the chain link 202 or chain 200.

The final stage of wear for the bite region 208 is represented by FIGS.13 and 14. At this stage, the ratio of the fourth thickness (not shownnow because it has disappeared) to the third thickness 230 has reachedzero. Now, the chain 200 or chain link 202 needs to be replaced as thecontact surface area 210 is reduced, making the chain 200 or chain link202 no longer useful in its intended application.

Referring now to FIGS. 15 and 16, both regions 236, 240 of the middleportions 220 of the chain link 202 have worn away, meaning that it isalso time to replace the chain 200 or chain link 202.

FIGS. 17 and 18 depict a scenario where the bottom surface 244 of onemiddle portions 220 has worn out. So, it may be necessary to rotate thechain 200 or chain link 202 ninety or one hundred eighty degrees aboutthe load vector L to continue using the chain. In order to rotate thechain link 180 degrees, it is desirable to check that the oppositecorresponding surface 244′ on the other middle portion 220′ has not wornaway. Alternatively, the chain 200 or chain link 202 could be replaced.

Lastly, FIGS. 19 and 20 show a scenario where the side surfaces 246 ofthe middle portions 220 of the chain link 202 have worn away, requiringthat the chain 200 or chain link 202 be rotated ninety degrees about theload vector L. Alternatively, the chain 200 or chain link 202 could bereplaced.

INDUSTRIAL APPLICABILITY

In practice, a chain link or chain according to any embodimentdescribed, shown or discussed herein may be sold, bought, manufactured,remanufactured, retrofitted, assembled or otherwise obtained in anaftermarket or OEM context.

A chain link according to any embodiment described herein may bedesigned using an existing chain link design and modifying the design asneeded or desired. For example, a chain link design having a trapezoidalshape may be changed to that shown in FIG. 6 where a substantiallysquare shape is provided having the same cross-sectional areas as theoriginal trapezoidal shape. In particular, the first thickness 212 forthe design in FIG. 6 is greater than the corresponding dimension locatedat the extremity 228 of the previous trapezoidal shape. At the sametime, the second thickness 218 may be approximately the same for theembodiment shown in FIG. 6 as the corresponding maximum trapezoidaldimension of the previous design. The cross-section in the rail ormiddle portions may remain much the same. Other design techniques arepossible.

A chain or chain link according to any embodiment described, discussedor shown herein may be used with the following method shown in FIG. 21for using or maintaining such a chain or chain link.

The method 300 includes inspecting a chain or chain link for signs ofwear without using tools (step 302). Then, if signs of wear aredetected, the method includes changing the orientation of the chain orthe chain link or replacing the chain (step 304). In some embodiments,the inspection step 302 is achieved without using tools to actuallymeasure wear (step 306). For example, no gauges, templates or othermeasuring tools may be needed. In other embodiments, the inspection step302 is achieved without using tools to assemble or disassembly the chainor a chain link (step 308). For example, no tools may be needed to pry achain link apart or separate one chain link from another chain link. Inother embodiments, one or more chain links are provided so that wear intwo or more directions are provided. In the embodiments shown in thefigures, wear in three directions that are substantially perpendicularto each other may be monitored simultaneously (step 310).

Once signs of wear are detected, the orientation of the chain or chainlink may be changed in various ways. In some embodiments, the chain orchain link may be rotated a predetermined amount (step 312). In somecases, this may be about the load vector and done in ninety degreeintervals. In other cases, this may be done about an axis perpendicularto the load vector such as Z-axis as shown in the figures. The amount ofchange in orientation may be any predetermined amount including thoseless than or greater than ninety degrees, etc.

It will be appreciated that the foregoing description provides examplesof the disclosed assembly and technique. However, it is contemplatedthat other implementations of the disclosure may differ in detail fromthe foregoing examples. All references to the disclosure or examplesthereof are intended to reference the particular example being discussedat that point and are not intended to imply any limitation as to thescope of the disclosure more generally. All language of distinction anddisparagement with respect to certain features is intended to indicate alack of preference for those features, but not to exclude such from thescope of the disclosure entirely unless otherwise indicated.

Recitation of ranges of values herein are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein, and eachseparate value is incorporated into the specification as if it wereindividually recited herein.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the embodiments of theapparatus and methods of assembly as discussed herein without departingfrom the scope or spirit of the invention(s). Other embodiments of thisdisclosure will be apparent to those skilled in the art fromconsideration of the specification and practice of the variousembodiments disclosed herein. For example, some of the equipment may beconstructed and function differently than what has been described hereinand certain steps of any method may be omitted, performed in an orderthat is different than what has been specifically mentioned or in somecases performed simultaneously or in sub-steps. Furthermore, variationsor modifications to certain aspects or features of various embodimentsmay be made to create further embodiments and features and aspects ofvarious embodiments may be added to or substituted for other features oraspects of other embodiments in order to provide still furtherembodiments.

Accordingly, this disclosure includes all modifications and equivalentsof the subject matter recited in the claims appended hereto as permittedby applicable law. Moreover, any combination of the above-describedelements in all possible variations thereof is encompassed by thedisclosure unless otherwise indicated herein or otherwise clearlycontradicted by context.

What is claimed is:
 1. A chain link comprising: a body including two endportions and two middle portions connecting the two end portionstogether, wherein at least one middle portion defines at least oneregion including at least one wear indicator, wherein the body defines acenter of mass and a Cartesian coordinate system with an X-axis, Y-axis,a Z-axis and an origin positioned at the center of mass, the endportions define a load vector for the body of the chain link and theX-axis of the coordinate system is oriented parallel with the loadvector, and the at least one middle portion defines a first surfacedefining a first surface normal that is non-parallel to the X-axis, theY-axis, and the Z-axis, and the at least one wear indicator is disposedon the first surface, and wherein the first surface normal isnon-parallel to the Z-axis and the Y-axis, and includes a first pocketdefined by the first surface.
 2. The chain link of claim 1, wherein theat least one wear indicator includes a first pocket defined by the firstsurface.
 3. The chain link of claim 2 1, wherein the first pocket iselongated along a direction parallel with the Z-axis X-axis defining itsmaximum dimension oriented along the Y-axis X-axis, the first pocketfurther defining a width along a direction parallel with the X-axisY-axis and a depth along a direction parallel with the Y-axis Z-axis. 4.The chain link of claim 3, wherein the at least one middle portiondefines a second surface defining a second surface normal that isnon-parallel to the X-axis.
 5. The chain link of claim 4, wherein thesecond surface includes a second wear indicator in the form of a secondpocket that is elongated along a direction parallel with the X-axisZ-axis defining its maximum dimension oriented along the X-axis Z-axis,the second pocket further defining a width along a direction parallelwith the Y-axis X-axis and a depth along a direction parallel with theZ-axis Y-axis.
 6. The chain link of claim 5, wherein second the firstpocket defines a bottom extremity positioned along a direction parallelwith the Z-axis, the first second pocket defines an end extremitypositioned along a direction parallel along the Z-axis, the Cartesiancoordinate system establishes a first X-Z X-Y plane positioned at theorigin of the Cartesian coordinate system and the body of the chain linkdefines a second X-Z X-Y plane spaced away from the first X-Z X-Y planethat is disposed between the bottom extremity of the second first pocketand the end extremity of the first second pocket.
 7. The chain link ofclaim 6, wherein the Cartesian coordinate system establishes a X-Y planeand a Y-Z, plane, and the body of the chain link is symmetrical aboutthe X-Y plane, the first X-Z plane and the Y-Z plane.
 8. A chainassembly comprising: at least two chain links interconnected with eachother; and at least one of the chain links includes a body including twoend portions, wherein at least one end portion defines a bite regionincluding a bite contact surface configured to contact the other chainlink and that defines a load vector, the at least one end portionincluding a first portion with a reduced cross-section defining a firstthickness measured along a direction that is non-parallel to the loadvector, and a raised rib disposed between the bite region and the firstportion along a direction parallel with the load vector, the raised ribdefining a second thickness along a direction that is non-parallel tothe load vector, wherein the second thickness is greater than the firstthickness; wherein the body defines a center of mass and a Cartesiancoordinate system with an X-axis, Y-axis, a Z-axis and an originpositioned at the center of mass, both the end portions defining a loadvector for the body of the at least one of the chain links and theX-axis of the coordinate system is oriented parallel with the loadvector, and the body further includes a first middle portion and asecond middle portion connecting the two end portions together, formingan enclosed perimeter, and the first middle portion defines a firstregion including a first wear indicator and a second region including asecond wear indicator that has an elongated shape that is perpendicularto the load vector.
 9. The chain assembly of claim 8, wherein the bodydefines a center of mass and a Cartesian coordinate system with anX-axis, Y-axis, a Z-axis and an origin positioned at the center of mass,both the end portions defining a load vector for the body of the atleast one of the chain links and the X-axis of the coordinate system isoriented parallel with the load vector, and the body further includes afirst middle portion and a second middle portion connecting the two endportions together, forming an enclosed perimeter.
 10. The chain assemblyof claim 9 8, wherein the at least one end portion defines a firstcurved portion extending from the first middle portion to the secondmiddle portion and the raised rib extends from the first middle portionto the second middle portion along the first curved portion.
 11. Thechain assembly of claim 10, wherein the body further defines a radiusedportion that transitions from the raised rib to the first portion with areduced cross-section.
 12. The chain assembly of claim 9 8, wherein thefirst middle portion and the second middle portion are straight,extending along a direction parallel to the X-axis.
 13. The chainassembly of claim 12, wherein the at least one middle portion defines afirst region including at least a first wear indicator, and a secondregion including at least a second wear indicator.
 14. The chainassembly of claim 13 12, wherein the first wear indicator has anelongated shape extending in a direction parallel to the load vector andthe second wear indicator has a second elongated shape extending in adirection perpendicular to the load vector.
 15. The chain assembly ofclaim 8, wherein the first and second thicknesses are measured in adirection perpendicular to the load vector and the ratio of the secondthickness to the first thickness ranges from 1.1 to 1.5.
 16. The chainassembly of claim 8, wherein the at least one end portion defines afirst extremity along a direction that is parallel to the load vectorand the first portion with a reduced cross-section defines a thirdthickness measured along a direction that is parallel to the load vectorfrom first extremity to the raised rib, and the raised rib defines afourth thickness measured along a direction that is parallel to the loadvector from the first portion with a reduced cross-section to the bitecontact surface, and a ratio of the fourth thickness to the thirdthickness ranges from 0.30 to 0.50.
 17. The chain assembly of claim 12,wherein the at least first wear indicator has an elongated shapeextending in a direction parallel to the load vector.
 18. A chain linkcomprising: a body including two end portions, wherein at least one endportion defines a bite region including a bite contact surface thatdefines a load vector, the at least one end portion including a firstportion with a reduced cross-section defining a first thickness measuredalong a direction that is non-parallel to the load vector, and a raisedrib disposed between the bite region and the first portion along adirection parallel with the load vector, the raised rib defining asecond thickness along a direction that is non-parallel to the loadvector, wherein the second thickness is greater than the firstthickness; and the body further includes a first middle portion and asecond middle portion connecting the two end portions together, and thefirst middle portion defines a first region including a first wearindicator and a second region including a second wear indicator that hasan elongated shape that is perpendicular to the load vector.
 19. Thechain link of claim 18, wherein the body defines a center of mass and aCartesian coordinate system with an X-axis, Y-axis, a Z-axis and anorigin positioned at the center of mass, both the end portions defininga load vector for the body, and the X-axis of the coordinate system isoriented parallel with the load vector.
 20. The chain link of claim 19,wherein the at least one end portion defines a first curved portionextending from the first middle portion to the second middle portion andthe raised rib extends from the first middle portion to the secondmiddle portion along the first curved portion.
 21. The chain link ofclaim 20, wherein the body further defines a radiused portion thattransitions from the raised rib to the first portion with a reducedcross-section.
 22. The chain link of claim 19, wherein the first middleportion and the second middle portion are straight, extending along adirection parallel to the X-axis.
 23. The chain link of claim 22,wherein the at least first wear indicator has an elongated shapeextending in a direction parallel to the load vector.
 24. The chain linkof claim 18, wherein the first wear indicator has an elongated shapeextending in a direction parallel to the load vector.
 25. The chain linkof claim 18, wherein the first and second thicknesses are measured in adirection perpendicular to the load vector and the ratio of the secondthickness to the first thickness ranges from 1.1 to 1.5.
 26. The chainlink of clam 18, wherein the at least one end portion defines a firstextremity along a direction that is parallel to the load vector and thefirst portion with a reduced cross-section defines a third thicknessmeasured along a direction that is parallel to the load vector fromfirst extremity to the raised rib, and the raised rib defines a fourththickness measured along a direction that is parallel to the load vectorfrom the first portion with a reduced cross-section to the bite contactsurface, and a ratio of the fourth thickness to the third thicknessranges from 0.30 to 0.50.
 27. A chain link comprising: a body includingtwo end portions and two middle portions connecting the two end portionstogether, wherein at least one middle portion defines at least oneregion including at least one wear indicator; and wherein the bodydefines a center of mass and a Cartesian coordinate system with anX-axis, Y-axis, a Z-axis and an origin positioned at the center of mass,the end portions define a load vector for the body of the chain link andthe X-axis of the coordinate system is oriented parallel with the loadvector, and the at least one middle portion defines a first surfacedefining a first surface normal that is non parallel to the Z-axis, andthe Y-axis, and a second surface defining a second surface normal thatis parallel to the Y-axis.
 28. The chain link of claim 27, wherein theat least one wear indicator includes a first pocket defined by the firstsurface.
 29. The chain link of claim 28, wherein the first pocket iselongated along a direction parallel with the X-axis defining itsmaximum dimension oriented along the X-axis, the first pocket furtherdefining a width along a direction parallel with the Y-axis and a depthalong a direction parallel with the Z-axis.
 30. The chain link of claim29, wherein the second surface includes a second wear indicator.
 31. Thechain link of claim 30, wherein the second wear indicator is in the formof a second pocket that is elongated along a direction parallel with theZ-axis defining its maximum dimension oriented along the Z-axis, thesecond pocket further defining a width along a direction parallel withthe X-axis and a depth along a direction parallel with the Y-axis. 32.The chain link of claim 31, wherein the Cartesian coordinate systemestablishes a X-Y plane, a X-Z plane, and a Y-Z, plane, and the body ofthe chain link is symmetrical about the X-Y plane, the X-Z plane and theY-Z plane.